vr4 dyno results

[94gt-sn2000]

well finally got my mustang tuned and made pretty good #'s, 489rwhp @5000 and 551rwtq @4400, it pulled stong and made 9.5 psi at 5000 but right at 5000rpm boost started falling off. I am only spinning the blower to 40,850 at 5000rpm and i know the vr4 can spin faster than that. i have the stock crank pulley and a 3.5 blower pulley(8 rib setup) i don't see any belt dust and the belt is pretty tight, do you think the belt is slipping or its internal? if i could get the boost to keep climing past 5000rpm i'd be in the 500+ rwhp club.
anyway another happy vr4 owner here, this blower is sweet,
Thanks for all the help Ryan

[pavement pounde]

Woow, good numbers congrats!
If the pressure on the balls is within tolerances the slipp should be the belt.
Even with my 10 rib setup I sse a little beltslip at max rpm but I don't want to much stress on my stock crank.